Thermocline Pool Heating · Heat pumps, gas & solar-thermal · Fellburn Heights & the Lagg Road · Since 2013
Warm water is a heating problem before it is a pool problem.
Thermocline heats pools the way an engineer would: a heat-loss audit before a hardware quote, a heater sized to your gallons and your season, and a cover in the contract because evaporation steals seventy percent of whatever you make. The running figure is printed in the proposal — modelled on your tariff, checked against your meter, and beaten or explained every year since.
THE HEATING ARGUMENT, SHORT VERSION: evaporation, not the air, is where pool warmth goes — the surface is a firehose pointed at the sky. Audit the losses first, size the plant second, cover the water third.
Why the shop exists
The audit before the appliance
Most pool heaters are sold the way furnaces were sold in 1960: by catalogue, to a guess. Ours start with arithmetic — your gallons, your surface, your wind exposure, your night temperatures and your target swim window — and the audit prints three numbers: the daily loss in kilowatt-hours, the plant that covers it, and the honest running cost per swim season. Then, and only then, somebody sells you a machine.
The printed running figure
The proposal names your season’s heating cost to the dollar, modelled on your tariff and your meter. Beat it and the audit was conservative; miss it by more than fifteen percent and the difference is credited against the fix — two claims in eleven years, both windy hillside pools that got the windbreak recommendation they declined.
What we do
What Thermocline sets & fixes
Air-source heat pumps
The Lagg Road default: a heat pump sized off the audit, plumbed after the filter and ahead of everything else, with a controller that reads the water and the weather before it spends a watt. Sized correctly a heat pump returns four to five kilowatts of warmth per kilowatt it draws — the COP figure in the ledger at the top of this page — and it does its best work slowly, overnight, on the cheap hours.
Gas on demand
For the households that swim hot and suddenly: a condensing gas heater that takes the pool from resting to race temperature inside a weekend, then steps back. The audit prices gas against heat-pump honestly — gas wins the sprint and loses the season — and plenty of our pools run both, each doing the half of the job it is actually good at.
Solar-thermal & the cover package
Mat arrays on the south roof and an automatic cover on the water: the sun tops the tank up all day and the cover stops the sky taking it back at night. The cover alone is worth more than a second heater on most Lagg Road pools — evaporation is seventy percent of the loss, and a covered pool simply refuses to give it up.
Services & rates
Heating, priced from
Prices from last season’s Lagg Road installs; the fixed number comes out of the audit, because a heater sized to a guess is money burned on purpose. The cover line is deliberately cheap against the plant lines — on most pools it is the highest-return heating hardware you can buy, and we would rather sell you the physics before the machinery.
The heat auditfree
Gallons, surface, exposure, tariff, target season — three printed numbers and no obligation
Air-source heat pump, installedfrom $7,900
Right-sized unit, pad, plumbing, controller, commissioning against the audit
Condensing gas heater, installedfrom $5,400
For fast recoveries and spa loops; gas line coordination included
Solar-thermal mat arrayfrom $4,600
Roof-mounted mats, circulation and bypass, sized to your surface
Automatic cover, heating specfrom $11,200
Slatted or track cover, retained-warmth certification, one-button close
Season tune & meter check$189 / visit
Refrigerant, combustion, flow and controls; the running figure re-proven annually
How it goes
Audit to first warm swim
The same sequence on every job — the only variable is your project.
Week 1
The heat audit
Ninety minutes at the pool: gallons computed from the shape, surface measured, wind and shade read, night temperatures pulled for your exact postcode, and your last two utility tariffs photographed. The three printed numbers — loss, plant, season cost — leave with you whether you buy anything or not.
Weeks 2–3
The proposal
Plant options side by side — heat pump, gas, solar-thermal, cover, and the honest pairings — each with its installed price and its modelled season figure. The cover is quoted on every proposal without exception; declining it is a choice we write down and respect.
Week 4
Set & commission
The install is a day or two: pad, plumbing, controller, and the commissioning hour where the output is measured against the plate rating with the meter running. A heat pump that cannot hit its numbers at commissioning goes back on the supplier’s truck, not your equipment pad.
Every season after
Tune, meter, true-up
The annual visit re-proves the running figure against your actual meter — the printed number from the audit, checked in public. Fleet median holds at sixty-four percent below pre-audit bills; your pool’s line in the ledger shows where it sits and why, windbreaks and all.
2025 — 2026, the Heights
Warm water, photographed in season
Six heated pools from last season, shot between October and April — the months a heated pool either justifies itself or becomes the most expensive ornament on the property. Steam in frame is authentic and unbilled.
Fair questions
Questions with thermometers in them
The five every Lagg Road kitchen reaches once the heating bill lands. The shop line answers seven to five, Fellburn time.
What will it actually cost to run?
The honest answer is a printed line, not a shrug: your gallons, your surface, your tariff, your season, modelled at the audit and trued against your meter every year after. The fleet median runs sixty-four percent below pre-audit bills, a covered forty-thousand-gallon pool on the Heights holds eighty-two degrees through October for about a hundred and forty dollars a month, and your proposal names your number before you sign.
Heat pump or gas — which one?
They are different tools, not rivals. A heat pump is a marathon runner: four to five watts back per watt drawn, happiest running long and slow overnight on cheap hours, unbeatable across a season. Gas is a sprinter: flat to race temperature inside a weekend, and priced like a sprint across a season. Spas and sudden swimmers favour gas; families who want a long warm season for a fixed figure favour the heat pump. The audit prices both and pairs them where the pool argues for it.
How fast will my pool heat up?
Slower than the movies: with realistic plant, a full pool rises three to five degrees a day, and the audit says exactly how many. That is why the controller works nights and why the cover matters — an uncovered pool can lose most of a day’s gain by breakfast, which is the arithmetic behind selling the physics before the machinery. Pools are kept warm, not repeatedly rescued.
Can you add heat to an existing pool?
That is most of the work, and the plumbing is the easy half: the audit reads what the pool already has — pump schedule, turnover hours, cover, exposure — before anything is bolted on. About a third of audits end with a controller and a cover and no new plant at all, because the cheapest heater is the one the water stops losing heat from.
What happens in winter?
Two honest roads. Season-extension keeps the pool at swim temperature into the shoulder months and lets it rest in deep winter — the plant drains down, the cover stays on, the freeze guard watches the plumbing. All-winter heating is done, but the audit will tell you what it costs before you commit, because a heated January on the Heights is a figure people deserve to see in print first.
Four heating seasons of guessing, then the audit: ninety minutes, three printed numbers, and the discovery that our heater was two sizes too big and our pool had no cover. Thermocline sold us the SMALLER plant, the cover and a controller, and the meter has run sixty-one percent lighter ever since — with the pool warmer, longer, than it ever was when we were paying more. I have recommended a heating company to strangers. Twice.
Free heat audits across Fellburn Heights & the Lagg Road · (555) 027-3354 · heat@thermocline.example
Book the heat audit
Ninety minutes at the pool, three printed numbers, no obligation — the loss, the plant, the season figure. Send the address and a rough shape; the audit does the rest. heat@thermocline.example